Version June 2024
| Platelet products |
| Source of platelets |
| Platelets can be prepared from units of whole blood and pooled ("whole blood derived [WBD]" or "pooled platelets") or obtained by apheresis ("apheresis" or "single-donor platelets"). The efficacy and risks of these products are similar, and they can be used interchangeably in most circumstances. In most centers, pooled platelets are less expensive. Single-donor platelets are necessary when histocompatible platelet transfusions (eg, HLA-A- and HLA-B-antigen-matched) are needed. |
| RhD alloimmunization |
| RhD alloimmunization in RhD-negative recipients can be prevented/reduced by using products from RhD-negative donors or by using anti-D immunoprophylaxis. The major risks of RhD alloimmunization are related to hemolytic disease of the fetus and newborn (HDFN). Thus, these approaches may be used for females with the potential for future childbearing. However, rates of RhD alloimmunization are low in patients with cancer, and these approaches need not be applied universally. |
| Leukoreduction |
| White blood cells (WBCs) present in the platelet product may cause alloantibody-mediated refractoriness to platelet transfusion in some individuals; leukoreduction can reduce this risk. It is appropriate to provide leukoreduced blood products (including platelets) to individuals with AML from the time of diagnosis. Leukoreduced products may also be useful for individuals with other types of leukemia, those with other types of cancer who are receiving chemotherapy, or those with other bone marrow disorders who require frequent transfusions. Other advantages of pre-storage leukoreduction include reduced rates of transfusion reactions and CMV transmission. The majority of blood products are pre-storage leukoreduced in many countries. |
| Prophylactic platelet transfusion thresholds* |
| Hematologic malignancies and allogeneic HSCT |
| Transfuse for a platelet count <10,000/microL. Higher thresholds may apply in certain circumstances (active bleeding, need for invasive procedure, fever, hyperleukocytosis, rapidly declining platelet count, anticipated delay in seeking care for bleeding [eg, outpatient who lives far from the treatment center], coagulation abnormalities such as in acute promyelocytic leukemia, or other indications based on the judgment of the treating clinician). |
| Autologous HSCT |
| Children: Same as described above for hematologic malignancies and allogeneic HSCT. |
| Adults: For the majority of patients, same as described above for hematologic malignancies and allogeneic HSCT. In some experienced centers, it may be appropriate to transfuse at the first sign of bleeding rather than prophylactically¶, based on evidence that the risk of severe bleeding is similar with this approach and platelet usage may be decreased. This approach requires ability to monitor the patient closely and to intervene rapidly at the first sign of bleeding. Clinical judgment applies. |
| Chronic stable severe thrombocytopenia in the absence of active treatment (eg, MDS, AA) |
| It may be appropriate to transfuse for bleeding or an invasive procedure or during active treatment. Clinical judgment applies. |
| Solid tumors |
| The risk of bleeding is related to the depth and duration of thrombocytopenia. Transfusion for a platelet count <10,000/microL is appropriate for most patients. Higher thresholds may apply in certain circumstances (active bleeding, need for invasive procedure, fever, necrotic tumor). |
| Surgical or invasive procedures |
| Major procedures: Transfusion for a platelet count <40,000 to 50,000/microL is appropriate for most procedures in most patients. |
| Minor procedures: Transfusion for a platelet count <20,000/microL is appropriate for selected procedures such as bone marrow aspirate/biopsy or insertion/removal of a central venous catheter. |
| Lumbar puncture: High-quality data are lacking. Other guidelines have suggested transfusion for a platelet count <50,000/microL. |
| Refractoriness to platelet transfusion |
| Diagnosis |
| Refractoriness to platelet transfusion may be suspected when the platelet count does not increase as expected following transfusion. In such cases, a post-transfusion platelet count should be obtained 10 to 60 minutes after all platelet transfusions if possible. Refractoriness to platelet transfusion may be diagnosed when transfusion of ABO-compatible platelets stored for <72 hours fails to result in a reasonable increase in platelet count 10 to 60 minutes after transfusion on at least two occasions. The expected increase may be determined by calculating the CCI; a CCI of ≥5000/microL is reasonable. Alternatively, an increment of ≥2000/microL for each unit in a pooled concentrate or ≥10,000/microL for each unit of single donor (apheresis) platelets is reasonable. For children, an increment of ≥3500/square meter for each apheresis unit is reasonable. |
| Management |
| Refractoriness may be due to immune or non-immune causes. Non-immune causes include fever, sepsis splenomegaly, and medications. Individuals with alloimmune refractoriness to platelet transfusions are best managed with transfusions from histocompatible donors matched for HLA-A and HLA-B antigens. Refer to the UpToDate topic on platelet refractoriness for further details. |
ASCO: American Society of Clinical Oncology; HLA: human leukocyte antigen; AML: acute myeloid leukemia; CMV: cytomegalovirus; HSCT: hematopoietic stem cell transplantation; MDS: myelodysplastic syndrome; AA: aplastic anemia; CCI: corrected count increment.
* Prophylactic platelet transfusions are administered to prevent bleeding in patients with thrombocytopenia when the platelet count drops below a certain threshold. The threshold depends on the patient's diagnosis, clinical status, and other treatments being administered.
¶ Refer to UpToDate for a discussion of UpToDate authors' approaches.آیا می خواهید مدیلیب را به صفحه اصلی خود اضافه کنید؟
